Lightning-arrester.



F. S. CHAPMAN.

LNGHTNING ARRESTER APPLICATION HLED MAY20.1910.

l 1 73,096. Patented Feb. 22, 1916.v

2 SHElTS-SHEETl.

F. S. CHAPMAN.

LIGHTNING ARRESTER.

APPLICATION FILED MAYZOfIQIO.

Patented Feb. 22, 1916.

Y UNITED sTATEs PATENT oEEioE.

FRANK S. CHAPMAN, OF TOLEDO, OHIO, ASSIGNOR TO THE 'NATIONAL ELECTRIC SPECIALTY COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO.

LIGHTNING-ARRESTER.

To all whom it may concern.' Be it known that I, FRANK S. CHAPMAN, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Lightning-Arresters, of which the following is a specification.-

My invention relates to a lightning arrester and has for its object to provide a device of this sort having certain new and improved constructions and arrangements to ybe hereinafter described and claimed.

One of the objects of the invention is to provide a lightning arrester constructed with a gap, or with gaps,facross which a static current of short duration, like a lightning discharge, may pass to ground without overheating or otherwise injuring the 'electrodes, and provided with means whereby the gap is Aclosed in the event that a continuous current of relatively high potential gets on the line, as for example, when the line becomes crossed with a high potential power line or the like, in which case, if such a current were permitted forany considerable length of time to arcacross the Fgap or gaps between the electrodes, the latter might be heated enough to destroy the usefulness of the lightning arrester. l

A further object of the invention is to provide in a lightning arrester, comprising electrodes contained within a vacuum chamber, a firm and durable mounting for the electrodes which will always keep the electrodes in the 'same relative positions.

vA further object of the invention is tov provide a. simple and convenient device whereby the lightning arrester may be so mounted that it can be removed, for repair Y or when it has`to be replaced by a new one,

without disconnecting the linel and ground wires.

A furtherl object of my invention is to provide a lightning arrester of the vacuum type in which a shield shall be interposed between the arcing zone and the adjacent surface of the exhausted container, especially the surface where the wires come through the container, whereby the container as well as the wires are protected` against the heat generated by the arc when the device discharges under a high potential.

A further object. of my invention is to provide such a device in which the intervSpecieaton of Letters Patent.l

Patented Feb. 22, 1916.

Application led May 20, 1910. Serial No. 562,416.

posed shield shall be separated from the protected surface of the container.

Another object of my invention is-to connect the carbon electrodes with the'groind and line wires by an intermediate member Figure 1 is a longitudinal sectional view, i

with parts shown in elevation, of the lightning arrester. Fig. 2 a sectional plan taken on line 2-2 of Fig. v1. Fig. 3 a 4sectional plan taken lon line 3 3 of Fig. l. Fig. 4c a side elevationbf one o f the electrodes, the upper part being shown in section. Fig. 5'

a diagram illustrating the wiring for a metallic circuit. Fig 6 a similar viewillustrating the wiring for a grounded'line. Fig. 7 a perspective view illustrating a preferred form of device for mounting the lightning arrester. Fig. 8 a perspective view of one of the porcelain blocks shown in the preceding figure, looking at the bottom of the same, andnFig. 9 a section taken on line 9--9 of Fig. 7, looking in the direction of the arrows.

Like characters of reference indicate like parts in the several figures of the drawings.

Referring to the drawings, 15 designates a porcelain base on which are mounted a pair of electrodes 16 consisting preferably of carbon plates, between which is -a third carbon plate 17. The carbon plates 16 and 17 are secured to the base 15 by means of the screws 18 which screw into extensions 19 at the bottom of the electrodes; the screws 18 .serving also as binding posts for the leadingin wires, as will be hereinafter described.

' By this arrangement it will be observed that during a discharge of the device the carbon electrodes will frst'become heated and by the indirect method of connecting the carbons with the leading in wires the tendency to overheat the wires will be lessened. Furthermore, in arresters of the vacuum type the heat generated by the arc during the discharge of the device is so intense that it has a tendency to melt the wallof the glass container-when the same is exposed to the direct heat of the arc and also has atendency to crack the glass, thereby admitting air and destroying the Vacuum, whereupon, because of the wide gap between the electrodes provided in a vacuum arrester and the higher resistance of atmospheric.y air, the device becomes inoperative. So, also, the intense heat of the arc tends to burn ofi' the leading in wires unless protected. It will be'seen, therefore, that I have interposed ashield between the/arcing zone and that portion of the container through which the leading in wires pass, consisting, first, of

a, porcelain base which is amore highly refractory material than glass, second, preferably of a layer4 of asbestos cement interposed between the arcing zone and the porcelain base, and thirdly by separating the porcelain base from the adjacent glass wall. Thus in the preferred embodiment of y vibration of passing trains.

4 5 f these separable balls or similar contact points The electrodes 16 are provided with metal cups 21 which contain the bodies of solderl 22, the latter being employedto secure in' place the, preferably, iron balls 23. The

balls 23 have ai diameter greater than the distance between the rims of cups 21 and are not essential to the broad features of my present invention in certain of its aspects above noted.`but constitute a modification which it is desirable to usein certain situations or for particular services.

The electrodes and the base on which they are mounted are contained within a Yglass bulb 24, or other suitable inclosing means,

vfrom which the air has been partially exhausted; the degree of vacuum dependingy upon the size of the spark-gaps, upon the sort of line on which the device is to be used and other obvious considerations relating to the design of the device# The device as described is intended to be used on a metallic circuit, the general relation of the parts being shown in the diagram of Fig. 5. A., in this figure, 'represents the instrument to be protected, B the line wire,

25-25 wires leading from the line wire Bf on each side of the instrument A to the electrodes 16; and 2G a wire leading from elec,- trode 17 to the ground.

For reasons which are well understood the portions of the leading-in wires of the device which pass through the glass stem 27 are made of platinum, these sections of wire being indicated at 28. The wires 2.5- 25 and 26are ordinarily copper.y Preferably,` in order to give a firm and rigid support of base 15, within the bulb 24, the portions of the leading-in wires within the bulb, indicated at 29, are of nickel orV other sti strong wire. This construction gave rise to certain difficulties which have been solved in the following nianner: In the device as constructed, I use iTo. 22 platinum wire and nickel wire of the same gage. difficulty in securing these wires together by methods which are well known. In order, however, to have the copper wire of the same carrying capacity electrically as.the

There is no This fused the platinum wirey but not the copper. So far, of course, the method employed isold. In order to fuse the copper I placed the'end of the copper wirefin a gas flame drawn to a ine point by an airflolast Iand heated the copper to redness or somewhat hotter, then brought the platinum wire into contact with the heated copper wire,

both wires being connected to the source of current supply, then drew the ends of the wires slightly apart, and e which fused both wires. While this method of producing a greater amount of heat in one of twoelements by supplementing the action of the iiame with that of an) electric current is especially adapted for 'and desirable in the step in the manufacture of my an arcing resulted lightning arrester', as described, it is obviousu i that this method might be employed in other situations. f y In Figs. 7, 8 and 9 I have illustrated a preferred form, of mounting for the light ning arrester o'f my, invention, the device being obviouslysuitable for use with other apparatus of a similar" character. 30 represents a porcelain block which maybe permanently secured'to a switchboard or other supporting `means by any suitable means (not shown). This block has the binding posts 31 for the leading-in wires 25 from securing to the block 30 a coupling plate 33.

. the line wire B (see Fig. 5) and the binding 34 is a porcelain block on which is mounted the lightning arrester or other similar piece of apparatus. This block has secured thereto the coupling plate 35 which may be attached to the coupling plate 33 by the screw 36; and the coupling plates 37, 37 which may be secured to the block 30 by the screws 38. The end 26a of the, ground wire 26 connects the plate 35 with the. electrode 17 Sections of wire 25, 25a connect the electrodes 16 with the plates 37 and sections of wire 25h, 25h connect the binding posts 31 with the corresponding screws 38. The block 34 is slotted as indicated at 39. By this arrangement, when it is necessary to remove the lightning arrester for repair, or in order to replace it withv a new one, by removing screw 34 and screws 38, block 34 may be detached from block 30-without disturbing the connections of the ground and line wires.

'The device, as above described, willoperate as follows: If a static discharge of short duration, even though it be of very high potential, gets on the line B, it will arc across the gap between the electrode 16 connected with the part of the line wire in questionV to the electrode 1-7 and thence to the ground,

A discharge of this sort will be so distributed over the electrodes and will be of such relatively short duration that, if the device is properly designed, the electrodes will not be overheated, nor will enough current beconcentrated in and around the bodies of solder 22 to melt them. It will be understood that the device is designed, having reference to the size of the gap and the inten- -sity of the vacuum to give a resistance high enough to prevent the normal current on the line from grounding. Nowif the line should by chance be crossed with a high potential line lfor example, say a line carrying 500 volts or more, the continuous current which would go over the gap between the electrodes, supposing them not to be provided with Athey balls, as above described, would in -time result in heating the device to a point l where it would be destroyed or made useless.

- which holds it in its cup,

. electrode 17.

This yis what sometimes occurs with lightning arresters constructed on this general principle. If, however, the electrodes 16V are provided with the balls 23 the high continuous potential current will concentrate on the ball in question and will melt the solder causing the ball to fall out of the socket against the grounded As the ball is too large to escape from the space between the electrodes it closes the gap between them for the current and thereupon the heating of the electrodes ceases. Vith the device. in this condition the line "Bis, of course, grounded and out of service. When the cross has been discovered and repaired the lightning arrester may be removed in they manner above described, and the proper wires connected in a battery circuit which will result in the melting of the upon the base 18 in order that their relative positions may be accurately fixed and maintained. If each electrode is supported on its leading-in wire, the heating-of the wires or .other disturbances may cause a displacement of one electrode with respect to the other,

which interferes with the proper operation of the device. n

In Fig. 6 I have illustrated diagrammatically an arrangement of a lightning arrester, constructed on the above principles for use in connection with a grounded circuit, there being in this case only two electrodes. A represents the instrument to be protected, B the line wire which is grounded as shown, 16a an electrode connected with the line wire by the wire b and 17a an electrode connected with the line wire on the other side, of instrument A by the wire b.

' As modifications in form, construction, arrangement and proportion of parts will readily suggest themselves to those skilled in this art, I do not limit myself to these particulars except so far as certain of the same may be made specific limitations on certain of the claims herein.

` Certain features of my invention, such, for example, as the use of the solder supported iron balls are adaptable for use in air gap arresters as well as in vacuum arresters.

I claim:

1. A lightning arrester comprising a pair of electrodes spaced so as to form a gap and a contact element secured to and in electrical contact with one of said electrodes and out of contact with theother which is moved into contact with the other of said electrodes by the heat generated at the gap due to an abnormal discharge across said gap.

2. A lightning arrester comprising a pair of electrodes arranged so that an open space intervenes between the same which can be traversed by a discharge without iniury to said electrodes, a contact element and a fusible material which is melted by a continued discharge lof abnormal voltage and by releasing said co-ntact element allows the same to close the space between said electrodes.

3. A lightning arrester comprising a pair of electrodes spaced so as to form a. gap, a contact element, and a fusible material which secures the contact element to and in electrical Contact with one of said electrodes and out of Contact with the other` said contact u element when released adapted to come into contact with said other electrode and close Y ysaid gap.

to and in electrical contact with one of said carbon plates and out 0f contact with the other; said ball being adapted when released by the melting yof the fusible material to come into contact with said other plate and close the gap between said plates.

5. A lightning arrester comprising a pair of carbon plates,.a cup secured to one of said plates, a body of solder in vsaid cup, and

a ball secured to said cup by'said solder;

tact element, and a fusible velement which normally holds said contact element out of i electrical contact with one of. said electrodes and which is adapted to be melted by a continued discharge of abnormal voltage so as to release said contact element and allow the same to close vthe space between said electrodes. i

Z. A lightning arrester "comprising a pair of carbon plates, a cup secured to one of said plates, a body of solder-in said cup, a ball secured to said cup by said solder; saidball being adapted when released by the melting of the solder to close the gap between said plates, and inclosing means for said plates and ball from which the air has been partially exhausted.

8. In a lightning arrester, the combination with a base of non-conducting material,

of a plurality of electrodes spaced apart and rigidly fixed to said base, and wires which support the base, vthe ends of which are bent over and bound against the under surface vof the base, andu means extending through said base for maintaining said wires 1n electrical connection with said electrodes.

9. In a lightning arrester, the combination with av glass bulb having a stem, of a base vof non-conducting material within said bulb, a plurality of electrodes spaced apart and rigidly fixed to said base, wires sealed through the neck of the bulb and bent over and bound against the under surface of said base, and means extending through the base for maintaining said wires in electrical connection with saidelectrodes.

1'0. In ay lightning arrester, Ythe combination with a glass bulb having a neck, of a porcelain base in said bulb, a plurality of carbon plates spaced apart, a body of asbestos cement securing said carbon plates to thc base, leading in wires sealed through the neck of said bulb and bent over and bound to the under side of said base, and means extending through the base for maintaining said wires in electrical connection with said electrodes.

11. A lightning arrester comprising in combination a vacuum chamber, a pair of electrodes arranged in said chamber so that an open space intervenes between them, a contact element, and a fusible material which secures said element to and in electrical contact vwith one of the electrodes; said fusible material adapted to be melted by a continued discharge of abnormal voltage so as to release the contact element Vand allow it to bridge the space between said electrodes.

12. A lightning arrester comprising they combination with an exhausted container, of

a base of non-conducting material mounted within said container, aI plurality of electrodes spaced apart and mounted upon said base, and wires sealed through the container and connecting with the electrodes.

13. In a lightning arrester, the combination with an exhausted glass container, of leading-in wires sealed through the wall of said container, a'base of refractory, nonconducting material within said container and spaced away from the seals of the leading-'in wires, a plurality of electrodes mounted onthe opposite side of said base from the leading-in wires, and means electrically connecting the leading-in wires with said electrodes.

14. In a lightningarrester, the combination with a glass bulb having a stem, of a base of non-conducting material within said bulb, a plurality of electrodes spaced apart and mounted upon said base, wires sealed through the neck of the bulb, and means eX- tending through the base for maintaining said wires in electrical connection with said electrodes. l

15. Inl a lightning arrester, the combination with a glass bulb, of a base of non-conducting material within said bulb, a plurality of electrodes spaced apart and mounted upon. said Ibase, Wires sealed through said bulb and in electrical connection with said electrodes respectively, said wires being arranged to support said base out of 'contact with the wall of said bulb.

16. In a vacuum lightning arrester, the combination with an evacuated glass container, of a leading-in wire sealed through the glass wall of the same, a base member of non-.conducting refractory material supported on saidj leading-in wire and spaced away from the seal thereof, and an electrode supported on the opposite side of said base member from the seal of the leading-in wire and electrically connected through the base with said wire, said base being arranged transversely with respect to the leading-in wire so that it provides a shield'intervening between the said electrode and the seal of said leading-in wire.

17. In a vacuum lightning arrester, the combination with an evacuated container, of a plurality of substantially parallel leadingin Wires sealed through the Wall of said container, a base supported on said Wires and spaced away from the seals of the same, a plurality of electrodes supported on the op- J posite side of 1slie base from said seals and electrically connected tlirougli the base With said leading-in Wires respectively, said base member being arranged transversely with respect to the leading-in Wires so that it pro- Vides a shield between the electrodes and the 10.Y

VVitn-esses:

G. Y. SKINNER,V L. L. D. CHAPMAN. 

